JavaScript DOM: Selecting Siblings

Summary: in this tutorial, you will learn how to select the next siblings, previous siblings, and all siblings of an element.

Let’s say you have the following list of items:

<ul id="menu">
    <li>Home</li>
    <li>Products</li>
    <li class="current">Customer Support</li>
    <li>Careers</li>
    <li>Investors</li>
    <li>News</li>
    <li>About Us</li>
</ul>

Get next siblings #

To get the next sibling of an element, you use the nextElementSibling attribute:

let nextSibling = currentNode.nextElementSibling;

The nextElementSibling returns null if the specified element is the last one in the list.

The following example uses the nextElementSibling property to get the next sibling of the list item that has the current class:

let current = document.querySelector('.current');
let nextSibling = current.nextElementSibling;

console.log(nextSibling);

Output:

<li>Careers</li>

In this example:

First, select the list item whose class is current using the querySelector().
Second, get the next sibling of that list item using the nextElementSibling property.

To get all the next siblings of an element, you can use the following code:

let current = document.querySelector('.current');
let nextSibling = current.nextElementSibling;

while(nextSibling) {
    console.log(nextSibling);
    nextSibling = nextSibling.nextElementSibling;
}

Get previous siblings #

To get the previous siblings of an element, you use the previousElementSibling attribute:

let current = document.querySelector('.current');
let prevSibling = currentNode.previousElementSibling;

The previousElementSibling property returns null if the current element is the first one in the list.

The following example uses the previousElementSibling property to get the previous siblings of the list item that has the current class:

let current = document.querySelector('.current');
let prevSiblings = current.previousElementSibling;

console.log(prevSiblings);

The following example selects all the previous siblings of the list item that have the current class:

let current = document.querySelector('.current');
let prevSibling = current.previousElementSibling;
while(prevSibling) {
    console.log(prevSibling);
    prevSibling = current.previousElementSibling;
}

Get all siblings of an element #

To get all siblings of an element, we’ll use the logic:

First, select the element’s parent whose siblings you want to find.
Second, select the first child element of that parent element.
Third, add the first element to an array of siblings.
Fourth, select the next sibling of the first element.
Finally, repeat the 3rd and 4th steps until no siblings are left. In case the sibling is the original element, skip the 3rd step.

The following function illustrates the steps:

let getSiblings = function (e) {
    // for collecting siblings
    let siblings = []; 
    // if no parent, return no sibling
    if(!e.parentNode) {
        return siblings;
    }
    // first child of the parent node
    let sibling  = e.parentNode.firstChild;
    
    // collecting siblings
    while (sibling) {
        if (sibling.nodeType === 1 && sibling !== e) {
            siblings.push(sibling);
        }
        sibling = sibling.nextSibling;
    }
    return siblings;
};

Put it all together:

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>JavaScript Siblings</title>
</head>
<body>
    <ul id="menu">
        <li>Home</li>
        <li>Products</li>
        <li class="current">Customer Support</li>
        <li>Careers</li>
        <li>Investors</li>
        <li>News</li>
        <li>About Us</li>
    </ul>
    
    <script>
        let getSiblings = function (e) {
            // for collecting siblings
            let siblings = []; 
            // if no parent, return no sibling
            if(!e.parentNode) {
                return siblings;
            }
            // first child of the parent node
            let sibling  = e.parentNode.firstChild;
            // collecting siblings
            while (sibling) {
                if (sibling.nodeType === 1 && sibling !== e) {
                    siblings.push(sibling);
                }
                sibling = sibling.nextSibling;
            }
            return siblings;
        };

        let siblings = getSiblings(document.querySelector('.current'));
        siblingText = siblings.map(e => e.innerHTML);
        console.log(siblingText);
    </script>
</body>
</html>

Output:

["Home", "Products", "Careers", "Investors", "News", "About Us"]

Summary #

The nextElementSibling returns the next sibling of an element or null if the element is the last one in the list.
The previousElementSibling returns the previous sibling of an element or null if the element is the first one in the list.
To get all siblings of an element, you can use a helper function that utilizes the nextElementSibling property.

Quiz #

Quiz

Understanding JavaScript Siblings

10 questions

Test your understanding of nextElementSibling and previousElementSibling properties in JavaScript DOM

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